package com.ayu.flink.wordcount;

import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.KeyedStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;

import java.util.Arrays;

/**
 * @Author: 徐林玉//作者及
 * @Date: 2022/3/21//完成日期
 * @Description: //
 * @Version: v0.0.1 // 版本信息
 * @Function List: // 主要函数及其功能
 * @Others: // 其它内容的说明
 * @History: // 历史修改记录
 **/
public class BoundedStreamWordCount
{
	public static void main(String[] args) throws Exception {
		// 1. 创建流式执行环境
		StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
		// 2. 读取文件
		DataStreamSource<String> lineDSS = env.readTextFile("input/words.txt");
		// 3. 转换数据格式
		SingleOutputStreamOperator<Tuple2<String, Long>> wordAndOne = lineDSS
				.flatMap((String line, Collector<String> words) -> {
					Arrays.stream(line.split(" ")).forEach(words::collect);
				})
				.returns(Types.STRING)
				.map(word -> Tuple2.of(word, 1L))
				.returns(Types.TUPLE(Types.STRING, Types.LONG));
		// 4. 分组
		KeyedStream<Tuple2<String, Long>, String> wordAndOneKS = wordAndOne
				.keyBy(t -> t.f0);
		// 5. 求和
		SingleOutputStreamOperator<Tuple2<String, Long>> result = wordAndOneKS
				.sum(1);
		// 6. 打印
		result.print();
		// 7. 执行
		env.execute();
	}

}
